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Note 12 - Stock-based Compensation (Details Textual) - USD ($) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | May 17, 2018
Share-Based Payment Arrangement, Option [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 6 years 3 months 18 days | 6 years 6 months |
The 2018 Equity Incentive Plan [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) |  |  |  |  | 1,300,000
Share-Based Payment Arrangement, Expense | $ 464,000 | $ 590,000 | $ 1,200,000 | $ 1,600,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expected Contractual Term Forfeiture Rate |  |  | 3.10% |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche One [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 1 year |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 5 years 6 months |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche Three [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 2 years |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 5 years 9 months |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche Four [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 5 years |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 6 years 6 months |  |
The 2018 Equity Incentive Plan [Member] | Restricted Stock [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) |  |  |  |  | 326,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | 38,372 |  | 38,372 |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  |  | 2 years 1 month 6 days |  |
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount | $ 3,500,000 |  | $ 3,500,000 |  |
The 2018 Equity Incentive Plan [Member] | Restricted Stock [Member] | Director [Member] | Minimum [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 1 year |  |
The 2018 Equity Incentive Plan [Member] | Restricted Stock [Member] | Director [Member] | Maximum [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 2 years |  |
The 2018 Equity Incentive Plan [Member] | Restricted Stock [Member] | Officers And Employees [Member] | Maximum [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 5 years |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | 190,432 |  | 190,432 |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) |  |  | 10 years |  |
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount | $ 2,100,000 |  | $ 2,100,000 |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  |  | 2 years 1 month 6 days |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Maximum [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) |  |  | 10 years |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Director [Member] | Minimum [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 1 year |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Officers And Employees [Member] | Share-Based Payment Arrangement, Tranche One [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage |  |  | 20.00% |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Officers And Employees [Member] | Maximum [Member] |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 5 years |  |

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